Patent GB-500110-A (GB)
Title: Dyeing of cellulosic material
IPC: D06P1/66
Filed: 1937-06-30
Abstract: 500,110. Dyeing cellulosic materials. EVANS, J. G., PIGGOTT, H. A., REYNOLDS, R. J. W., ROSE, J. D., WALKER, E. E., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. June 30, 1937, No. 18241. [Classes 2 (iii) and 16 (ii)] To increase the affinity of cellulosic material for acid wool or acid chrome dyes it is treated with formaldehyde or a substance yielding formaldehyde and, at a relatively low temperature, preferably room temperature, with a solution of a compound containing (A) a substituted ammonium group free from any aliphatic substituent with more than 8 carbon atoms and (B) one of the groups -CO.NH2, -NH.CO.NH2 or -O.CO.NH2, and the material, so treated, is heated to 100-140‹ C. Alternatively, a preformed condensation product of formaldehyde with the compound may be used. The groups (A) and (B) may be linked by one of the groups -CH2-, -CH2. CO.NH-, -CH2.CH2.NH-, -CH2.CH2.O-, -C6H4.NH- or -CH2.CH2-. Some of the compounds suitable are obtainable by the processes described in Specifications 497,043, 497,368, and 497,485. Specified cellulosic materials are cotton, linen, jute, regenerated cellulose fibres or films, paper and cardboard. Regenerated cellulose fibres so treated may be dyed in admixture with wool. The impregnation is preferably effected in presence of an acid, e.g. boric, acetic, tartaric, lactic or tannic acid, or of an acid-yielding substance, e.g. ammonium dihydrogen phosphate, chloride or thiocyanate or sodium bisulphite and the heat treatment may be effected in presence of an acid vapour. In examples: (1) cotton limbric is impregnated with an aqueous solution at room temperature containing ammonium dihydrogen phosphate and the condensation product of formaldehyde with #-ureidoethyl pyridinium chloride, squeezed, dried rapidly in warm air at 60‹ C., heated for 5 minutes at 120‹ C., rinsed and dyed with Azo geranine 2G or Fast acid violet A2R; (2) a viscose rayon fabric is impregnated with a cold aqueous solution containing ammonium dihydrogen phosphate, #-ureidoethylpyridinium chloride, and formaldehyde, squeezed and dried as in (1), heated for ¢ hour at 140‹ C. and dyed with acid wool dyestuffs; (3) viscose rayon stockinette is impregriated with a cold aqueous solution containing ammonium dihydrogen phosphate, carbamylmethylpyridinium chloride or trimethyl-p-ureidophenylammonium methosulphate and formaldehyde, further treated as in (2) and dyed with acid wool or acid chrome dyestuffs; the heating at 140‹ C. may be replaced by a steaming at atmospheric or slightly increased pressure; (4) viscose rayon fabric is impregnated with an aqueous solution of hydroxymethylcarbamylmethylpyridinium chloride, squeezed, heated for ¢ hour at 140‹ C. and dyed with Tartrazine N; (5) viscose staple fibre is impregnated with an aqueous solution containing ammonium dihydrogen phosphate, carbamylmethylpyridinium chloride and formaldehyde, squeezed, dried in hot air at 60‹ C., heated for ¢ hour at 140‹ C. and dyed with Orange G or Solochrome black T ; (6) viscose fabric is impregnated as in (5) using less formaldehyde, squeezed, heated for ¢ hour at 140‹ C. and dyed with Coomassie navy blue 2RNX.